java变量的引用传递

package bianliang;

public class Hero {
    
    
	


	public static void main(String[] args) {
    
    
		// TODO Auto-generated method stub
		
		Demo demo=new Demo();
		Swap(demo);
		System.out.println(demo.attr1+"\t"+demo.attr2);
			
	}
	
	
	 static class Demo{
    
    
		int attr1=10;
		int attr2=50;
	}
	public static void Swap(Demo demo) {
    
    
		 demo=new Demo(); 
		int temp=demo.attr1;
		 demo.attr1=demo.attr2;
		 demo.attr2=temp;
		
	}

}

输出为：10 50

package bianliang;

public class Hero {
    
    
	


	public static void main(String[] args) {
    
    
		// TODO Auto-generated method stub
		
		Demo demo=new Demo();
		Swap(demo);
		System.out.println(demo.attr1+"\t"+demo.attr2);
			
	}
	
	
	 static class Demo{
    
    
		int attr1=10;
		int attr2=50;
	}
	public static void Swap(Demo demo) {
    
    
		
		int temp=demo.attr1;
		 demo.attr1=demo.attr2;
		 demo.attr2=temp;
		
	}

}

输出为：50 10